1. Field of the Invention
In fuel injection systems for direct-injection internal combustion engines, fuel injectors that contain one or more electrically triggerable valves are employed. For instance, an electrically triggerable magnet valve or piezoelectric valve may be provided for controlling a needle valve and thus for controlling the course of injection. Further valves may be used, for instance for a pressure boost. Separately testing the functionality of the various valves and the components connected to these valves or controlled by these valves, however, is often a challenge.
2. Prior Art
Since the electrically triggerable valve or valves are typically accommodated in the interior of an injector body, the production, testing and electrical contacting of these electrically triggerable valves as well as maintenance of the electrically triggerable valves often present considerable technical difficulties.
In many cases, on top of the injector body there is an electrical contact that can be connected to a corresponding control system and power supply system located outside the injector body. Via this contact (which may be either a plug with multiple contacts, or a plurality of individual plugs), all the electrically triggerable valves received in the interior of the injector body are as a rule triggered. In the interior of the injector body, this electrical contact must be connected to corresponding contacts of the electrically triggerable valve or valves of the injection system. This connection is typically done by means of flexible electrical cables and a simple soldering process.
This method for electrically contacting the electrically triggerable valves is associated with various disadvantages, however. For instance, the method is technically quite labor-intensive, since typically the cables must be initially soldered by hand against the corresponding electrical contacts. In practice, this method step requires great effort and is very time-consuming. Moreover, the connection between the electrically triggerable valves and the electrical contact on the injector body can be undone again only with difficulty. For removing or disassembling the injector body, soldered or welded connections must typically be disconnected again. Such a labor-intensive process makes it uneconomical to repair the injectors or replace individual parts of the injector body.
Moreover, in this method, testing the various functionalities of the fuel injectors sometimes presents major problems. In many cases, if a malfunction occurs in testing in the installed state, the fuel injector must be disassembled again, which is labor-intensive. Once the repair or replacement of individual components (such as of an electrically triggerable valve) has been done and the parts have been installed again, the functionality must then be tested again. In many cases, this method is too labor-intensive and thus uneconomical.